You're actually very wrong on this point at a very basic level. You can't be really good at something by focusing only on it. To be good at software design, y

You're actually very wrong on this point at a very basic level. You can't be really good at something by focusing only on it. To be good at software design, you need to be good at understanding computers and people. You need to understanding programming, design, marketing, hiring, management, etc. Scott Adams developed this into a concept he named "The Talent Stack". You can easily verify it: find billionairs who got rich from X, study their profile, you will find they have a wide range of skills outside of X. For any such X you can also find many individuals with exceptional ability/knowledge about X but not much else, and they are often far less successful from people with a wide range of skills.